Answer:
(d) all of the above
Explanation:
before cutting the screw threads the operator should lubricate all of the machine parts given in the option that is lead screw and gearbox , the ways and the cross slide and the carriage and half-nuts. we should use lubrication because it reduces the overall system friction and if friction is reduced then heat generated due to friction is also decreases which is beneficial
so option (D) will be correct because we need lubricate in all the given parts
Answer: A, B, C & F (interacting w computers, making decisions & solving problems, evaluating information & getting information).
Explanation: Those are the correct & verified answers.
Answer:
Explanation:
(c). looking for the radiation of the collector is given thus
C = 0.095 + 0.04 sin [360/365(n-100)] = 0.095 + 0.04 sin [360/365(1-100)]
C = 0.05535
∴ Diffuse radiation of the collector Idc = C*Ib + (1+cosσ/2)
Idc = 0.5535 * 908.7 (1+cos40/ 2) = 44.41 W/m²
Idc = 44.41 W/m²
Answer:
investor claim is acceptable
Explanation:
given data
Win = 0.25 kW
Qc = 3000 J/s = 3kW
Th = 293 K
Tc = 270 K
solution
we get here coefficient of performance of cycle is
coefficient of performance =
..................1
put here value and we get
coefficient of performance =
coefficient of performance = 1.2
and
coefficient of performance of ideal refrigeration is
coefficient of performance =
..................2
coefficient of performance =
coefficient of performance = 11.74
and
we can see here that coefficient of performance of ideal refrigeration is is more than real cycle coefficient of performance
so investor claim is acceptable
Answer:
(b) Given the Weibull parameters of example 11-3, the factor by which the catalog rating must be increased if the reliability is to be increased from 0.9 to 0.99.
Equation 11-1: F*L^(1/3) = Constant
Weibull parameters of example 11-3: xo = 0.02 (theta-xo) = 4.439 b = 1.483
Explanation:
(a)The Catalog rating(C)
Bearing life:
Catalog rating: 
From given equation bearing life equation,

we Dividing eqn (2) with (1)

The Catalog rating increased by factor of 1.26
(b) Reliability Increase from 0.9 to 0.99

Now calculating life adjustment factor for both value of reliability from Weibull parametres


Similarly

Now calculating bearing life for each value

Now using given ball bearing life equation and dividing each other similar to previous problem

Catalog rating increased by factor of 0.61